Bogus Messiah

Lu Yu, a man who seemingly lacked empathy, was acutely aware of his emotional detachment. Despite this disconnect, he harbored an intense desire to write novels that could touch minds and hearts. How this individual, so starkly lacking in emotional depth, could manifest the intricate tapestry of a novel remained a topic of heated debate.
Amidst a bus ride discussing his future, a piercing scream shattered the tranquility. The passengers' eyes collectively turned towards the origin of this distressing cry, and what they beheld was a scene that belonged to the realm of nightmares.
In front of them, a horrifying scene was playing out: a man, compelled by madness, was biting into the throat of a young boy. The shock was intensified by the chilling fact that this wasn't a horror movie but a real-time sinister spectacle. Fear spread like wildfire among the passengers, igniting an instinctual urge to escape. Amidst the chaos, Lu Yu, near the exit, got trampled, his escape cut short by injuries.
Yet fate intervened. A stranger, claiming time-traveler status, imparted a chilling apocalyptic truth and a survival guide, vanishing as mysteriously as he had appeared.
Could an aspiring, emotionally distant writer alter the world's course, or is he going to die along with the world?